The present invention is directed to a two-step method for the production of a pressure sensitive adhesive by radiation curing.
It is well known that pressure sensitive adhesives may be prepared by radiation curing of monomer admixtures. See, for example, U.S. Pat. Nos. 4,181,752; 4,379,201; 4,421,822; 4,513,039; 4,522,870; 4,587,313; 4,665,106; 5,183,833; 4,737,559; 5,302,629; 5,462,977; 5,536,759; 5,552,451; 5,618,899 and 5,683,798. Indeed, attempts have been made to provide reinforced pressure sensitive adhesives by incorporating reinforcing macromers in the radiation curable composition. See, for example, PCT/US97/09601 and WO94/13750.
It is, however, desirable to provide a method for the production of a macromer-free pressure sensitive adhesive by radiation curing which does not require the presence of a reinforcing macromer to yield a pressure sensitive adhesive exhibiting desirable adhesive properties.